Thrust stabilizing hydraulic mechanism



1965 c. E. M MANAMA THRUST STABILIZING HYDRAULIC MECHANISM Filed Feb. 18, 1963 INVENTOR. CHARLES E. Mc MANAMA United States Patent 3,213 906 THRUST STABILIZING HiZDRAULIC MEUHANISM Charles E. McManama, Potlatch, Idaho Filed Feb. 18, 1963, Ser. No. 259,254 3 Claims. (Cl. 14319) In the use of horizontal bandsaw sawmills which tra- Verse in sawing upon a rectangular guide rail frame that is adjustably supported upon a log to saw desired thicknesses of lumber therefrom, it is seen desirable to have a mechanism to cut down vibration and shaking that might occur because the lineal members of the supporting guide rail may not be adequately rigid when sawing some kinds of logs. This mechanism as designed reduces the required thickness and weight of the guide rail frame considerably by transferring the thrust of the saw directly to the log at properly spaced intervals along the guide rail.

This hydraulic stabilizing mechanism is therefore of particular value for hand portable sawmills of this type, and has the qualities of positive action, lightweight, ease of control, and low cost. The system is composed of a number of hydraulic cylinders spaced along the guide rail member in which inward thrust is encountered, which when extended have positive contact with the log, causing the guide rail to gain the same ridigity as the log. These cylinders having a relatively small bore for fast action are extended by a hand operated piston pump of a larger bore at the operators position at the end of the guide rail, and when a pressure release valve is opened the cylinders are equally retracted by matched return springs. In order to compensate for the loosening effect of vibration upon the engaging spindles of the hydraulic cylinders there is a hydraulic accumulator in the hydraulic pressure system between the pump and the cylinders which maintains a continuing pressure, and a check valve between the hydraulic accumulator and the cylinders which makes the hydraulic pressure rigid against the spindles of said cylinders.

In use, this hydraulic stabilizing mechanism is retracted and re-engaged every time the guide rail is adjusted to saw another board.

FIGURE 1 of the accompanying drawing shows a top view of a sawmill as described and how the stabilizing mechanism is applied.

FIGURE 2 show a side view of such a sawmill.

FIGURE 3 shows a sectional end view of such a sawmill along line 3-3 of FIGURE 2 and how the stabilizing mechanism is applied.

FIGURE 4 shows a diagram view of the hydraulic system of said stabilizing mechanism.

Relating to the accompanying drawing, when hydraulic pressure is pumped to cylinders a by hand operated piston pump 0, hydraulic spindles b with sharp ends d engage the log 2. The hydraulic accumulator f hydraulically interconnects between the pump 0 and check valve i maintaining a continued engagement pressure made rigid by check valve i. Upon opening pressure release valve g the spindles b return to a retracted position, actuated by matched return springs, the actuating fluid returning to reservoir j from which it was pumped.

Reference characters for fundamental parts of the sawmill not directly related to the invention are x, the rectangular guide rail frame composed of parallel side rails adjoined by end cross members; y, the traversing saw and saw carriage; and z, means of adjustable support upon the log being sawed.

Having thereby described my invention which I desire to protect by Letters Patent, I claim as original invention:

1. In a portable sawmill having a horizontal rectangular frame adapted to surround a log, a pair of laterally spaced side rails, cross members connecting said side rails adjacent the opposite ends thereof respectively, a horizontal bandsaw slidably mounted on said rails for sawing the log, and a supporting device mounted on each of said cross members for engaging the opposite ends of the log which adjustably supports the sawmill upon the log in a manner that desired thicknesses of lumber may be sawed therefrom; a saw thrust stabilizing mechanism comprising a number of single-acting spring-returned hydraulic cylinders lineally spaced upon that side rail which the saw thrust pulls toward the log, piston spindles of the hydraulic cylinders having sharpened means upon their ends to engage the side of the log when extended and convey the thrust force directly to the log, and a hydraulic system for extending the piston spindles.

2. A mechanism as set forth in claim 1, the hydraulic system of which comprises a manually operated piston pump having a common pressure line to all aforesaid hydraulic cylinders, and a return line connecting the pressure line directly to the reservoir from which the fluid is pumped, said return line having a control valve.

3. A mechanism as set forth in claim 2 having within said hydraulic system a hydraulic accumulator attached to the pressure line, a check valve in the pressure line to prevent the return of fluid to the accumulator from said cylinders, and said return line from the cylinders connected to the pressure line at a point between the cylinders and the check valve.

References Cited by the Examiner UNITED STATES PATENTS 1,317,132 9/19 Hill 143-125 2,264,375 12/41 Hill et a1 5l 2,318,163 5/43 Kahr. 2,609,848 9/52 Schneider. 2,916,883 12/59 Geck 92130 FOREIGN PATENTS 904,386 2/45 France.

WILLIAM W. DYER, JR., Primary Examiner. DONALD R. SCHRAN, Examiner. 

1. IN A PORTABLE SAWMILL HAVING A HORIZONTAL RECTANGULAR FRAME ADAPTED TO SURROUND A LOG, A PAIR OF LATERALLY SPACED SIDE RAILS, CROSS MEMBERS CONNECTING SAID SIDE RAILS ADJACENT THE OPPOSITE ENDS THEREOF RESPECTIVELY, A HORIZONTAL BANDSAW SLIDABLY MOUNTED ON SAID RAILS FOR SAWING THE LOG, AND A SUPPORTING DEVICE MOUNTED ON EACH OF SAID CROSS MEMBERS FOR ENGAGING THE OPPOSITE ENDS OF THE LOG WHICH ADJUSTABLY SUPPORTS THE SAWMILL UPON THE LOG IN A MANNER THAT DESIRED THICKNESSES OF LUMBER MAY BE SAWED THEREFROM; A SAW THRUST STABILIZING MECHANISM COMPRISING A NUMBER OF SINGLE-ACTING SPRING-RETURNED HYDRAULIC CYLINDERS LINEALLY SPACED UPON THAT SIDE RAIL WHICH THE SAW 